International journal of energy and water resources, Nov 29, 2021
In the Ojekwe region of southern Benue, Nigeria, groundwater is the primary source of water for b... more In the Ojekwe region of southern Benue, Nigeria, groundwater is the primary source of water for both home and agricultural use. The underlying geology determines the quality and availability of groundwater in the region. The hydrogeochemistry of groundwater was examined, as well as its suitability for drinking and irrigation. The American Public Health Association (APHA) standard method was used to analyze physicochemical characteristics in 24 groundwater samples. The water quality index (32–39) revealed that groundwater samples have good water quality, implying that the groundwater is safe to drink. Permeability Index (PI), Soluble Sodium Percentage (SSP), Sodium Percentage (Na%), Sodium Absorption Ratio (SAR), Kelly Ratio (KR), and Magnesium Hazard (MH) range from 0.00 to 0.01, 4.04 to 412.9, 0.63 to 257.7, 0.15 to 2.34, 0.09 to 2.57, and 6.84 to 84.55, respectively. According to irrigation indices, total hardness (TH) results (40–256) indicate that groundwater is classified as soft (40–66), moderately hard (83–149), or hard (151–256). Estimated results from the Chloride–sulfate mass ratio (CSMR), Revelle index (RI), and Larson–Skold index (LSI), which range from 0.00 to 2.66, 0.00 to 0.57, and 0.04 to 1.92, respectively, revealed corrosion and salinization influenced groundwater at particular sampling locations. However, chloride and sulfate were unlikely to interfere with natural forming film.
International Journal of Applied Science and Engineering Research, 2015
The characteristics of Abakaliki clays from southeastern Nigeria were characterized to establish ... more The characteristics of Abakaliki clays from southeastern Nigeria were characterized to establish its suitability as drilling mud when compared with Wyoming bentonite. The chemical, mineralogical and geotechnical properties were employed in assessing the suitability of Abakliki clay as drilling mud. Mineralogically, the clays were all characterized as dominantly Illite as well as montmorillonite with low percentages of kaolinite. The chemical composition of the clays indicates low percentages of Na2O when compared with that of Wyoming bentonite with fairly higher percentages of CaO and K2O than are required for drilling mud clays. The clays are plastic; with liquid limit (LL) of 58 8 to 72.8, plastic limit (PL) of 25 to 30 and plasticity index (API) of 26 to 45.8. They classify as inorganic clays of high plasticity (CH) according to Unified Soil Classification System (USCS) and as A-7-6 according to American Association of State High and Transportation Official's (AASHTO) classif...
International Journal of Agriculture and Forestry, 2015
Physical properties of soil such as bulk density, total porosity, gravimetric moisture content, h... more Physical properties of soil such as bulk density, total porosity, gravimetric moisture content, hydraulic conductivity and soil texture can determine its suitability for the purpose of waste disposal. In this work, physical properties of soil that play a role in effluent transportation down ground water was studied. These properties included the bulk density, total porosity, gravimetric moisture content, hydraulic conductivity and soil texture. Three (3) samples were collected from each site at a soil depth of about 0-60 cm using a core sampler attached to a soil auger. Summary of the results from the four Dumpsites shows that they all have sandy texture, high total porosity (Water works 53. 1%, New layout 58.3%, Rice mill site 60.4%, and Iyiokwu 54.2%), high hydraulic conductivity (63.2 cm/hr for Water Works, 125.3 cm/hr for New layout, 47.8 cm/hr for Rice mill and 59.4 cm/hr for lyiokwu), high bulk density (1.24 g/cm 3 for Water Works, 1.11 g/cm 3 for New layout, 1.05 g/cm 3 for Rice mill and 1.21 for Iyiokwu), high affinity for moisture due to their general low moisture content (33.9% for water works, 42.3% for new layout, 38.1% for Rice mill site and 30.6% for Iyiokwu). Hence, all are susceptible to infiltration. However, the higher clay contents ( 307 /1000 for Water Works, 190 /1000 for New layout, 240 /1000 for Rice mill site and 163 /1000 for Iyiokwu) and higher Bulk Densities of the water works and Iyiokwu Dumpsites will cause the sites to have minimal infiltration rate. While the Water Works and the Iyiokwu dumpsites could be retained on the grounds of clay content and bulk density, it is recommended that the New layout and Rice mill dumpsites be relocated to a better site to prevent potential threats to groundwater.
Benthic foraminiferal turnover during the Palaeocene–Eocene Thermal Maximum (PETM) has been exten... more Benthic foraminiferal turnover during the Palaeocene–Eocene Thermal Maximum (PETM) has been extensively studied but numerous questions remained unresolved, question such as why some foraminiferal species went into extinction at a particular location but survive in another or why some species survive in extremely low oxygen environment. Because foraminiferal community interaction with the environment is driven by biological traits instead of taxonomic composition, this study has adopted trait-based approach to provide insight into the life strategies of foraminifera that enables them to survive in extreme environmental conditions. The result from this study shows that traits such as test composition, perforation, ornamentation and living habits play an important role in the ecological functioning and adaptability of foraminifera in the environment. The faunal assemblage in the studied site is dominantly cosmopolitan taxa suggesting the environment was perturbed during the PETM. Foraminiferal composition is characterised by faunal turnover indicated in extensive mortalities and extinction of both planktonic and benthic fauna. The ordination (non-metric dimensional scaling) of faunal composition also indicated ecological disturbance. The planktonic community was relatively stable before and after PETM but experienced a high level of ecological perturbation during the carbon isotopic excursion (CIE). The benthic community showed higher evidence of perturbation as the fauna assemblage ordination indicated that ecological stress started before the PETM with the disarray of samples in the ordination diagram. Only the recovery interval experienced some level of ecological stability. The environmental disturbance noticed in the fauna composition reflected on the trait. Benthic foraminiferal traits indicated instability throughout the studied section. The evidence of environmental disturbance in the benthic community suggests that the source of the light carbon that caused the PETM may have originated beneath sea floor in the Atlantic Ocean. Keywords Foraminifera · PETM · Ecological functions · Biological traits · Palaeoecology · Marine environment · Climate change · Atlantic Ocean
Benthic foraminiferal turnover during the Palaeocene–Eocene Thermal Maximum (PETM) has been exten... more Benthic foraminiferal turnover during the Palaeocene–Eocene Thermal Maximum (PETM) has been extensively studied but numerous questions remained unresolved, question such as why some foraminiferal species went into extinction at a particular location but survive in another or why some species survive in extremely low oxygen environment. Because foraminiferal community interaction with the environment is driven by biological traits instead of taxonomic composition, this study has adopted trait-based approach to provide insight into the life strategies of foraminifera that enables them to survive in extreme environmental conditions. The result from this study shows that traits such as test composition, perforation, ornamentation and living habits play an important role in the ecological functioning and adaptability of foraminifera in the environment. The faunal assemblage in the studied site is dominantly cosmopolitan taxa suggesting the environment was perturbed during the PETM. Foraminiferal composition is characterised by faunal turnover indicated in extensive mortalities and extinction of both planktonic and benthic fauna. The ordination (non-metric dimensional scaling) of faunal composition also indicated ecological disturbance. The planktonic community was relatively stable before and after PETM but experienced a high level of ecological perturbation during the carbon isotopic excursion (CIE). The benthic community showed higher evidence of perturbation as the fauna assemblage ordination indicated that ecological stress started before the PETM with the disarray of samples in the ordination diagram. Only the recovery interval experienced some level of ecological stability. The environmental disturbance noticed in the fauna composition reflected on the trait. Benthic foraminiferal traits indicated instability throughout the studied section. The evidence of environmental disturbance in the benthic community suggests that the source of the light carbon that caused the PETM may have originated beneath sea floor in the Atlantic Ocean. Keywords Foraminifera · PETM · Ecological functions · Biological traits · Palaeoecology · Marine environment · Climate change · Atlantic Ocean
Benthic foraminiferal turnover during the Palaeocene–Eocene Thermal Maximum (PETM) has been exten... more Benthic foraminiferal turnover during the Palaeocene–Eocene Thermal Maximum (PETM) has been extensively studied but numerous questions remained unresolved, question such as why some foraminiferal species went into extinction at a particular location but survive in another or why some species survive in extremely low oxygen environment. Because foraminiferal community interaction with the environment is driven by biological traits instead of taxonomic composition, this study has adopted trait-based approach to provide insight into the life strategies of foraminifera that enables them to survive in extreme environmental conditions. The result from this study shows that traits such as test composition, perforation, ornamentation and living habits play an important role in the ecological functioning and adaptability of foraminifera in the environment. The faunal assemblage in the studied site is dominantly cosmopolitan taxa suggesting the environment was perturbed during the PETM. Foraminiferal composition is characterised by faunal turnover indicated in extensive mortalities and extinction of both planktonic and benthic fauna. The ordination (non-metric dimensional scaling) of faunal composition also indicated ecological disturbance. The planktonic community was relatively stable before and after PETM but experienced a high level of ecological perturbation during the carbon isotopic excursion (CIE). The benthic community showed higher evidence of perturbation as the fauna assemblage ordination indicated that ecological stress started before the PETM with the disarray of samples in the ordination diagram. Only the recovery interval experienced some level of ecological stability. The environmental disturbance noticed in the fauna composition reflected on the trait. Benthic foraminiferal traits indicated instability throughout the studied section. The evidence of environmental disturbance in the benthic community suggests that the source of the light carbon that caused the PETM may have originated beneath sea floor in the Atlantic Ocean. Keywords Foraminifera · PETM · Ecological functions · Biological traits · Palaeoecology · Marine environment · Climate change · Atlantic Ocean
Amangwu-Edda, lies within the Afikpo Sub-Basin, a sedimentary basin set up during the late Cretac... more Amangwu-Edda, lies within the Afikpo Sub-Basin, a sedimentary basin set up during the late Cretaceous period following the Santonian uplift in the southern Benue Trough. Local stratigraphy and field relationship show that the lithologic succession consists of black to dark grey, fossiliferous and gypsiferous shales with subordinate limestone lenses and siltstone. Palynological analysis of the shale samples collected from the surface outcrops in the area yielded a total of 117 palynomorphs, made of 24 pollen species, 9 spore species and 19 dinoflagellate species, while foraminifera biostratigraphic analysis yielded 68 forams. The abundance of the pollen species of Longapertites sp., Monosulcites sp., and Monocolpites marginatus, the spore species of Cyathidites minor, Laevigatosporites sp., along with the dinoflagellate cysts species of Leoisphaeridia sp, Andallusiella sp., and Senegalinium sp, and especially a high abundance of the foraminifera species Bolivina anambra, suggest a ne...
The study area is underlain by igneous intrusives and shales of the Asu River Group (Albian) in t... more The study area is underlain by igneous intrusives and shales of the Asu River Group (Albian) in the southern Benue Trough, Nigeria. The massive mining operations in the Oshiri–Ishiagu mining axis have necessitated investigation of effects of mining works on water resources in the adjoining areas. Assessment of water resources around the study area was carried out to ascertain concentrations of trace elements/heavy metals using atomic absorption spectrophotometer. Results revealed some chemical pollutants with ranges of the concentration values (in mg/l) as thus: Cd (0.18–4.37), Pb (0.06–10.11), Zn (0.13–7.11), Ni (0.02–1.21), Mn (0.04–1.16), Fe (0.03–2.04) and Cr (0.02–0.48) in surface water regime, as well as Cd (0.02–2.00), Pb (0.16–3.18), Zn (0.13–5.16), Ni (0.01–1.54), Mn (0.01–2.17), Fe (0.01–2.50) and Cr (0.01–0.28) in groundwater system. Except Mn and Ni which showed higher contamination in groundwater than in the surface water representative samples, other pollutants exhibited higher amount of contamination and metal pollution indices in surface water resources. Principal component analysis showed that pollution of water resources is controlled by mining of Pb–Zn loads as indicated in principal component (PC1) through loading of Pb, Zn and Fe as eigen values. Excess loading of SO 4 2− in PC2 and PC3 signified that ions were released by dissolution process via breaking down (weathering) of the sulfide-associated ore. Dispersion of the ionic plumes was meteorologically aided, possibly by run-off and leaching; hence, the eigen of HCO 3 at − 0.49 in PC4. Strong association of these elements in Pearson correlation confirmed the anthropogenic-induced dissolutions and geogenic-aggravated dispersions. So, deterioration of water resources by mine drainage hampers potable water supply across the studied areas and may have affected the adjacent regions.
Abstract Field and lithostratigraphic studies of sediments of Eze-Aku Group in the Afikpo Synclin... more Abstract Field and lithostratigraphic studies of sediments of Eze-Aku Group in the Afikpo Synclinorium were carried out to define the lithostratigraphic status of the Amasiri Sandstone unit of the group. The study involved field mapping, description of outcrops and lithofacies analysis. Lithostratigraphic study shows that the group comprises marine shales and limestones overlain by succession of dominant sandstones alternating with shales. Five major lithofacies associations deposited in tidal shallow shelf to deep water depositional setting were revealed in this study: massive, conglomeritic sandstone, laminated sandstone, bioturbated sandstone, laminated shale and cross bedded sandstone facies associations. Two component formations were identified for the Eze-Aku Group in the basin: the late Cenomanian-early Turonian Eze-Aku Shale (transgressive phase) and the middle-late Turonian Amasiri Sandstone (regressive phase). The Eze-Aku Shale and Amasiri Sandstone represent lower boundary and unit stratotypes respectively. The cross bedded sandstones represent the uppermost part of the formation. Results of field studies also show that the Eze-Aku Group in Afikpo Synclinorium is bounded above and below by Santonian unconformity and late Albian – middle Cenomanian unconformity respectively.
This study was undertaken to determine the depositional environment, provenance and tectonic sett... more This study was undertaken to determine the depositional environment, provenance and tectonic setting for the Turonian Amasiri Sandstone, southern Benue Trough, Nigeria, using lithofacies analysis and re-appraisal of petrography of the sandstones. Local stratigraphy and field relationships show a thick succession of shales alternating with elongate/parallel sandstone ridges extending eastwards from Akpoha to Amasiri through Itigidi and Ugep to Apiapum areas. Lithofacies analysis reveals 9 lithofacies suggestive of storm (mass flow) and tidal shelf processes. These include dark grey to black laminated shale/silty mudstones, bioturbated mudstones, coquinoid limestones, very fine-grained bioturbated sandstones with shell hash/debris in places and limestone rip-up clasts, massive and chaotic sandy conglomerate with rip – up clasts, fine to medium-grained, parallel laminated sandstone, hummocky cross-stratified, massive, medium to coarse-grained sandstones, medium to very coarse-grained, planar cross-bedded sandstone, with clay-draped foresets and Ophiomorpha burrows, and coarse-grained trough cross-bedded sandstone. Petrofacies analysis identifies the sandstones as feldspathic and arkosic arenites. Ternary plot of framework mineralogy indicates derivation from an uplifted continental block related to the nearby Oban Massif and Cameroon Basement Complex.
International journal of energy and water resources, Nov 29, 2021
In the Ojekwe region of southern Benue, Nigeria, groundwater is the primary source of water for b... more In the Ojekwe region of southern Benue, Nigeria, groundwater is the primary source of water for both home and agricultural use. The underlying geology determines the quality and availability of groundwater in the region. The hydrogeochemistry of groundwater was examined, as well as its suitability for drinking and irrigation. The American Public Health Association (APHA) standard method was used to analyze physicochemical characteristics in 24 groundwater samples. The water quality index (32–39) revealed that groundwater samples have good water quality, implying that the groundwater is safe to drink. Permeability Index (PI), Soluble Sodium Percentage (SSP), Sodium Percentage (Na%), Sodium Absorption Ratio (SAR), Kelly Ratio (KR), and Magnesium Hazard (MH) range from 0.00 to 0.01, 4.04 to 412.9, 0.63 to 257.7, 0.15 to 2.34, 0.09 to 2.57, and 6.84 to 84.55, respectively. According to irrigation indices, total hardness (TH) results (40–256) indicate that groundwater is classified as soft (40–66), moderately hard (83–149), or hard (151–256). Estimated results from the Chloride–sulfate mass ratio (CSMR), Revelle index (RI), and Larson–Skold index (LSI), which range from 0.00 to 2.66, 0.00 to 0.57, and 0.04 to 1.92, respectively, revealed corrosion and salinization influenced groundwater at particular sampling locations. However, chloride and sulfate were unlikely to interfere with natural forming film.
International Journal of Applied Science and Engineering Research, 2015
The characteristics of Abakaliki clays from southeastern Nigeria were characterized to establish ... more The characteristics of Abakaliki clays from southeastern Nigeria were characterized to establish its suitability as drilling mud when compared with Wyoming bentonite. The chemical, mineralogical and geotechnical properties were employed in assessing the suitability of Abakliki clay as drilling mud. Mineralogically, the clays were all characterized as dominantly Illite as well as montmorillonite with low percentages of kaolinite. The chemical composition of the clays indicates low percentages of Na2O when compared with that of Wyoming bentonite with fairly higher percentages of CaO and K2O than are required for drilling mud clays. The clays are plastic; with liquid limit (LL) of 58 8 to 72.8, plastic limit (PL) of 25 to 30 and plasticity index (API) of 26 to 45.8. They classify as inorganic clays of high plasticity (CH) according to Unified Soil Classification System (USCS) and as A-7-6 according to American Association of State High and Transportation Official's (AASHTO) classif...
International Journal of Agriculture and Forestry, 2015
Physical properties of soil such as bulk density, total porosity, gravimetric moisture content, h... more Physical properties of soil such as bulk density, total porosity, gravimetric moisture content, hydraulic conductivity and soil texture can determine its suitability for the purpose of waste disposal. In this work, physical properties of soil that play a role in effluent transportation down ground water was studied. These properties included the bulk density, total porosity, gravimetric moisture content, hydraulic conductivity and soil texture. Three (3) samples were collected from each site at a soil depth of about 0-60 cm using a core sampler attached to a soil auger. Summary of the results from the four Dumpsites shows that they all have sandy texture, high total porosity (Water works 53. 1%, New layout 58.3%, Rice mill site 60.4%, and Iyiokwu 54.2%), high hydraulic conductivity (63.2 cm/hr for Water Works, 125.3 cm/hr for New layout, 47.8 cm/hr for Rice mill and 59.4 cm/hr for lyiokwu), high bulk density (1.24 g/cm 3 for Water Works, 1.11 g/cm 3 for New layout, 1.05 g/cm 3 for Rice mill and 1.21 for Iyiokwu), high affinity for moisture due to their general low moisture content (33.9% for water works, 42.3% for new layout, 38.1% for Rice mill site and 30.6% for Iyiokwu). Hence, all are susceptible to infiltration. However, the higher clay contents ( 307 /1000 for Water Works, 190 /1000 for New layout, 240 /1000 for Rice mill site and 163 /1000 for Iyiokwu) and higher Bulk Densities of the water works and Iyiokwu Dumpsites will cause the sites to have minimal infiltration rate. While the Water Works and the Iyiokwu dumpsites could be retained on the grounds of clay content and bulk density, it is recommended that the New layout and Rice mill dumpsites be relocated to a better site to prevent potential threats to groundwater.
Benthic foraminiferal turnover during the Palaeocene–Eocene Thermal Maximum (PETM) has been exten... more Benthic foraminiferal turnover during the Palaeocene–Eocene Thermal Maximum (PETM) has been extensively studied but numerous questions remained unresolved, question such as why some foraminiferal species went into extinction at a particular location but survive in another or why some species survive in extremely low oxygen environment. Because foraminiferal community interaction with the environment is driven by biological traits instead of taxonomic composition, this study has adopted trait-based approach to provide insight into the life strategies of foraminifera that enables them to survive in extreme environmental conditions. The result from this study shows that traits such as test composition, perforation, ornamentation and living habits play an important role in the ecological functioning and adaptability of foraminifera in the environment. The faunal assemblage in the studied site is dominantly cosmopolitan taxa suggesting the environment was perturbed during the PETM. Foraminiferal composition is characterised by faunal turnover indicated in extensive mortalities and extinction of both planktonic and benthic fauna. The ordination (non-metric dimensional scaling) of faunal composition also indicated ecological disturbance. The planktonic community was relatively stable before and after PETM but experienced a high level of ecological perturbation during the carbon isotopic excursion (CIE). The benthic community showed higher evidence of perturbation as the fauna assemblage ordination indicated that ecological stress started before the PETM with the disarray of samples in the ordination diagram. Only the recovery interval experienced some level of ecological stability. The environmental disturbance noticed in the fauna composition reflected on the trait. Benthic foraminiferal traits indicated instability throughout the studied section. The evidence of environmental disturbance in the benthic community suggests that the source of the light carbon that caused the PETM may have originated beneath sea floor in the Atlantic Ocean. Keywords Foraminifera · PETM · Ecological functions · Biological traits · Palaeoecology · Marine environment · Climate change · Atlantic Ocean
Benthic foraminiferal turnover during the Palaeocene–Eocene Thermal Maximum (PETM) has been exten... more Benthic foraminiferal turnover during the Palaeocene–Eocene Thermal Maximum (PETM) has been extensively studied but numerous questions remained unresolved, question such as why some foraminiferal species went into extinction at a particular location but survive in another or why some species survive in extremely low oxygen environment. Because foraminiferal community interaction with the environment is driven by biological traits instead of taxonomic composition, this study has adopted trait-based approach to provide insight into the life strategies of foraminifera that enables them to survive in extreme environmental conditions. The result from this study shows that traits such as test composition, perforation, ornamentation and living habits play an important role in the ecological functioning and adaptability of foraminifera in the environment. The faunal assemblage in the studied site is dominantly cosmopolitan taxa suggesting the environment was perturbed during the PETM. Foraminiferal composition is characterised by faunal turnover indicated in extensive mortalities and extinction of both planktonic and benthic fauna. The ordination (non-metric dimensional scaling) of faunal composition also indicated ecological disturbance. The planktonic community was relatively stable before and after PETM but experienced a high level of ecological perturbation during the carbon isotopic excursion (CIE). The benthic community showed higher evidence of perturbation as the fauna assemblage ordination indicated that ecological stress started before the PETM with the disarray of samples in the ordination diagram. Only the recovery interval experienced some level of ecological stability. The environmental disturbance noticed in the fauna composition reflected on the trait. Benthic foraminiferal traits indicated instability throughout the studied section. The evidence of environmental disturbance in the benthic community suggests that the source of the light carbon that caused the PETM may have originated beneath sea floor in the Atlantic Ocean. Keywords Foraminifera · PETM · Ecological functions · Biological traits · Palaeoecology · Marine environment · Climate change · Atlantic Ocean
Benthic foraminiferal turnover during the Palaeocene–Eocene Thermal Maximum (PETM) has been exten... more Benthic foraminiferal turnover during the Palaeocene–Eocene Thermal Maximum (PETM) has been extensively studied but numerous questions remained unresolved, question such as why some foraminiferal species went into extinction at a particular location but survive in another or why some species survive in extremely low oxygen environment. Because foraminiferal community interaction with the environment is driven by biological traits instead of taxonomic composition, this study has adopted trait-based approach to provide insight into the life strategies of foraminifera that enables them to survive in extreme environmental conditions. The result from this study shows that traits such as test composition, perforation, ornamentation and living habits play an important role in the ecological functioning and adaptability of foraminifera in the environment. The faunal assemblage in the studied site is dominantly cosmopolitan taxa suggesting the environment was perturbed during the PETM. Foraminiferal composition is characterised by faunal turnover indicated in extensive mortalities and extinction of both planktonic and benthic fauna. The ordination (non-metric dimensional scaling) of faunal composition also indicated ecological disturbance. The planktonic community was relatively stable before and after PETM but experienced a high level of ecological perturbation during the carbon isotopic excursion (CIE). The benthic community showed higher evidence of perturbation as the fauna assemblage ordination indicated that ecological stress started before the PETM with the disarray of samples in the ordination diagram. Only the recovery interval experienced some level of ecological stability. The environmental disturbance noticed in the fauna composition reflected on the trait. Benthic foraminiferal traits indicated instability throughout the studied section. The evidence of environmental disturbance in the benthic community suggests that the source of the light carbon that caused the PETM may have originated beneath sea floor in the Atlantic Ocean. Keywords Foraminifera · PETM · Ecological functions · Biological traits · Palaeoecology · Marine environment · Climate change · Atlantic Ocean
Amangwu-Edda, lies within the Afikpo Sub-Basin, a sedimentary basin set up during the late Cretac... more Amangwu-Edda, lies within the Afikpo Sub-Basin, a sedimentary basin set up during the late Cretaceous period following the Santonian uplift in the southern Benue Trough. Local stratigraphy and field relationship show that the lithologic succession consists of black to dark grey, fossiliferous and gypsiferous shales with subordinate limestone lenses and siltstone. Palynological analysis of the shale samples collected from the surface outcrops in the area yielded a total of 117 palynomorphs, made of 24 pollen species, 9 spore species and 19 dinoflagellate species, while foraminifera biostratigraphic analysis yielded 68 forams. The abundance of the pollen species of Longapertites sp., Monosulcites sp., and Monocolpites marginatus, the spore species of Cyathidites minor, Laevigatosporites sp., along with the dinoflagellate cysts species of Leoisphaeridia sp, Andallusiella sp., and Senegalinium sp, and especially a high abundance of the foraminifera species Bolivina anambra, suggest a ne...
The study area is underlain by igneous intrusives and shales of the Asu River Group (Albian) in t... more The study area is underlain by igneous intrusives and shales of the Asu River Group (Albian) in the southern Benue Trough, Nigeria. The massive mining operations in the Oshiri–Ishiagu mining axis have necessitated investigation of effects of mining works on water resources in the adjoining areas. Assessment of water resources around the study area was carried out to ascertain concentrations of trace elements/heavy metals using atomic absorption spectrophotometer. Results revealed some chemical pollutants with ranges of the concentration values (in mg/l) as thus: Cd (0.18–4.37), Pb (0.06–10.11), Zn (0.13–7.11), Ni (0.02–1.21), Mn (0.04–1.16), Fe (0.03–2.04) and Cr (0.02–0.48) in surface water regime, as well as Cd (0.02–2.00), Pb (0.16–3.18), Zn (0.13–5.16), Ni (0.01–1.54), Mn (0.01–2.17), Fe (0.01–2.50) and Cr (0.01–0.28) in groundwater system. Except Mn and Ni which showed higher contamination in groundwater than in the surface water representative samples, other pollutants exhibited higher amount of contamination and metal pollution indices in surface water resources. Principal component analysis showed that pollution of water resources is controlled by mining of Pb–Zn loads as indicated in principal component (PC1) through loading of Pb, Zn and Fe as eigen values. Excess loading of SO 4 2− in PC2 and PC3 signified that ions were released by dissolution process via breaking down (weathering) of the sulfide-associated ore. Dispersion of the ionic plumes was meteorologically aided, possibly by run-off and leaching; hence, the eigen of HCO 3 at − 0.49 in PC4. Strong association of these elements in Pearson correlation confirmed the anthropogenic-induced dissolutions and geogenic-aggravated dispersions. So, deterioration of water resources by mine drainage hampers potable water supply across the studied areas and may have affected the adjacent regions.
Abstract Field and lithostratigraphic studies of sediments of Eze-Aku Group in the Afikpo Synclin... more Abstract Field and lithostratigraphic studies of sediments of Eze-Aku Group in the Afikpo Synclinorium were carried out to define the lithostratigraphic status of the Amasiri Sandstone unit of the group. The study involved field mapping, description of outcrops and lithofacies analysis. Lithostratigraphic study shows that the group comprises marine shales and limestones overlain by succession of dominant sandstones alternating with shales. Five major lithofacies associations deposited in tidal shallow shelf to deep water depositional setting were revealed in this study: massive, conglomeritic sandstone, laminated sandstone, bioturbated sandstone, laminated shale and cross bedded sandstone facies associations. Two component formations were identified for the Eze-Aku Group in the basin: the late Cenomanian-early Turonian Eze-Aku Shale (transgressive phase) and the middle-late Turonian Amasiri Sandstone (regressive phase). The Eze-Aku Shale and Amasiri Sandstone represent lower boundary and unit stratotypes respectively. The cross bedded sandstones represent the uppermost part of the formation. Results of field studies also show that the Eze-Aku Group in Afikpo Synclinorium is bounded above and below by Santonian unconformity and late Albian – middle Cenomanian unconformity respectively.
This study was undertaken to determine the depositional environment, provenance and tectonic sett... more This study was undertaken to determine the depositional environment, provenance and tectonic setting for the Turonian Amasiri Sandstone, southern Benue Trough, Nigeria, using lithofacies analysis and re-appraisal of petrography of the sandstones. Local stratigraphy and field relationships show a thick succession of shales alternating with elongate/parallel sandstone ridges extending eastwards from Akpoha to Amasiri through Itigidi and Ugep to Apiapum areas. Lithofacies analysis reveals 9 lithofacies suggestive of storm (mass flow) and tidal shelf processes. These include dark grey to black laminated shale/silty mudstones, bioturbated mudstones, coquinoid limestones, very fine-grained bioturbated sandstones with shell hash/debris in places and limestone rip-up clasts, massive and chaotic sandy conglomerate with rip – up clasts, fine to medium-grained, parallel laminated sandstone, hummocky cross-stratified, massive, medium to coarse-grained sandstones, medium to very coarse-grained, planar cross-bedded sandstone, with clay-draped foresets and Ophiomorpha burrows, and coarse-grained trough cross-bedded sandstone. Petrofacies analysis identifies the sandstones as feldspathic and arkosic arenites. Ternary plot of framework mineralogy indicates derivation from an uplifted continental block related to the nearby Oban Massif and Cameroon Basement Complex.
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